Sequence variations and genetic differentiations in 16S rRNA gene in three geographic populations of Siberian prawn Exopalaemon modestus
ZHANG Min-ying, XU Dong-po, FANG Di-an, ZHOU Yan-feng, LIU Kai
Scientific Observing and Experimental Station of Fishery Resources and Environment in the Lower Reaches of the Changjiang River, Ministry of Agriculture, Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences,Wuxi 214081, China
Abstract: Purified PCR products were sequenced and part sequences of mitochondrial 16S rRNA gene were obtained in 129 individuals of Siberian prawn Exopalaemon modestus collected from Taihu Lake, Poyanghu Lake and Xingkaihu Lake among three geographic populations of Siberian prawn in order to study genetic variations in Siberian prawn. The results showed that 10 variable sites (2.06% of total nucleotides)were found in 486 bp fragment, and that 8 haplotypes were observed by analysis of haplotypes, including 5 haplotypes in Taihu Lake population, 4 ones in Poyanghu Lake population and 1 one(HapⅣ) in Xingkaihu Lake population. HapⅠwas shared by populations from Taihu Lake and Poyanghu Lake, Hap Ⅳ was shared by populations from Poyanghu Lake and Xingkaihu Lake,and no haplotype was shared by all the populations. There was average haplotype diversity (Hd) of 0.691 00 and the nucleotide diversity (Pi) of 0.002 46, indicating low genetic diversity in the three populations. Analysis of molecular variance (AMOVA) revealed that genetic variation was 70.42% within the populations and the genetic variation of 29.58% among three populations, with genetic differentiation index (Gst) of 0.295 8 and gene flow(Nm) of 0.595 2, indicating that there was very significant genetic differentiation among three populations(P<0.01). The findings provide basic data for germplasm conservation of Siberian prawn.